Justin_B Posted June 13, 2009 Share Posted June 13, 2009 Being new to this Oilhead stuff (longtime Airhead) I am wondering just exactly what is it that you are describing as a "surge"? To me a surge is the feeling of the throttle being rythmicaly "goosed" a bit when you haven't done anything... I have a condition on my "new to me" 30k mile 2004 R1150 RT-P which some might describe as a surge when I barely back off the throttle to slow slightly while cruising at speed. Let's say I've been poking along at 65 MP and roll off the throttle just a hair. What happens is almost like the throttle has been closed considerably, my speed will drop about 10 MPH, then (if I've kept my throttle in the same exact position) the power will kick back in and the bike accelerates back to where it should have wound up at originally. Is this the "dreaded surge" so often complained about? The 30k service had just been done B4 the cops traded 'em in on brand new ones. If this isn't the "surge" is it something that should keep a sane person from starting out on a 3000 mile jaunt or is it a "live with it 'til you figure it out" deal because it's just a minor annoyance that's not gonna make you walk for long distances? Thanks in advance... Link to comment
NoHeat Posted June 13, 2009 Share Posted June 13, 2009 Justin, you didn't mention the RPM where you experienced this. Also, does your 2004 RTP have dual spark plugs? I think complaints of surge are most common for older single-spark oilheads. My experience, with my single-spark oilhead before tuning up and installing a Techlusion, was that surge occurred while holding a constant throttle position with the engine running at around 3000 RPM, and never at high RPMS like 5000. For me it was most profound in 1st and 2nd gear, and less profound in higher gears. The engine seemed to hunt for the best fueling rate, and unable to find it, the fueling increased and decreased back and forth between two levels, at time intervals that are less regular than 'rhythmic'. Link to comment
Eric S Posted June 13, 2009 Share Posted June 13, 2009 Justin, you didn't mention the RPM where you experienced this. Also, does your 2004 RTP have dual spark plugs? I think complaints of surge are most common for older single-spark oilheads. My experience, with my single-spark oilhead before tuning up and installing a Techlusion, was that surge occurred while holding a constant throttle position with the engine running at around 3000 RPM, and never at high RPMS like 5000. For me it was most profound in 1st and 2nd gear, and less profound in higher gears. The engine seemed to hunt for the best fueling rate, and unable to find it, the fueling increased and decreased back and forth between two levels, at time intervals that are less regular than 'rhythmic'. I have a 98 R1100RT and you've just described my experience to a T. The bike currently has 15,500 miles on it. What to do? Link to comment
Justin_B Posted June 13, 2009 Author Share Posted June 13, 2009 I think this model is supposed to be dual-plug but I haven't taken it apart to verify. What you are describing is not what I am experiencing. I was curious as there are a few Techlusion boxes up for sale on flea-bay and wondered if they would help me in any way... Link to comment
11101110 Posted June 13, 2009 Share Posted June 13, 2009 above 4k rpm and 25mph I have little to no surge on my 2002. Now if I happen to find a road with a particular down grade that requires light throttle to just to spin the engine to keep from decellerating then I might get some surge. I have never experienced it at highway speeds. do a valve adjust and TB ballance before adding any aftermarket stuff. Link to comment
ShovelStrokeEd Posted June 13, 2009 Share Posted June 13, 2009 It is a fueling issue and may have something to do with the O2 sensor. As described, it is typically around 3000 RPM and very light throttle openings. My solution has always been to just ride around it. 4000 RPM solves the problem. You can tell if your bike has the dual plugs easily. The plug covers will say Twin Spark on them. If a good valve adjustment and throttle body synch doesn't cure the problem, I would go with a PCIII USB which will allow you to custom tailor a map to tune the problem out. Unlike a Techlusion, which will only add fuel, the former will allow you to lean out certain ranges and give better fuel economy as well. You do need to know what you are doing to take best advantage though. Messing with fuel and ignition maps is a really good way to damage a motor. Link to comment
ianboydsnr Posted June 13, 2009 Share Posted June 13, 2009 If its a twinspark, they surge when one of the coilpacks fail, most singlespark surging happens when they need a tune up, my 2000 model recently surged after a good service, replaced the new sparkplugs with the old ones and the surging stopped, my 2003 twinspark gs only surged when a coilpack failed. Link to comment
NoHeat Posted June 13, 2009 Share Posted June 13, 2009 My experience, with my single-spark oilhead before tuning up and installing a Techlusion, was that surge occurred while holding a constant throttle position with the engine running at around 3000 RPM, and never at high RPMS like 5000. For me it was most profound in 1st and 2nd gear, and less profound in higher gears. The engine seemed to hunt for the best fueling rate, and unable to find it, the fueling increased and decreased back and forth between two levels, at time intervals that are less regular than 'rhythmic'. I have a 98 R1100RT and you've just described my experience to a T. The bike currently has 15,500 miles on it. What to do? Unlike the original post in this thread, you've got the famous surge for single-spark oilheads. What to do? Tuneup, with valve adjust, new spark plugs (some swear by Autolite), and throttle body sync. If that doesn't fix the problem, then either live with it or install an after-market fueling box (Techlusion or Power Commander) to add fuel during low-RPM cruise. Link to comment
smiller Posted June 13, 2009 Share Posted June 13, 2009 If a good valve adjustment and throttle body synch doesn't cure the problem, I would go with a PCIII USB which will allow you to custom tailor a map to tune the problem out. Unlike a Techlusion, which will only add fuel, the former will allow you to lean out certain ranges and give better fuel economy as well. An even more important advantage of the Power Commander is that it will let you set your own closed loop mixture rather just blindly adding fuel. Set the PC to within a 13.8 - 14.1:1 range and surging will be gone, almost plug 'n play... (except for installing the new O2 sensor that comes with it, but that's not hard.) Link to comment
Justin_B Posted June 14, 2009 Author Share Posted June 14, 2009 Good info. I'll start out with a good sync and take it from there. I shouldn't think a coil was going bad at 30k miles so I'll file that away for futures... Link to comment
AndyS Posted June 15, 2009 Share Posted June 15, 2009 I think this model is supposed to be dual-plug but I haven't taken it apart to verify. What you are describing is not what I am experiencing. I was curious as there are a few Techlusion boxes up for sale on flea-bay and wondered if they would help me in any way... Looking at your wee picture, You have a twin spark. Surging should not be an issue on twin spark models. However, misbehaving stick coils are very much an issue and are worth swapping with a friends bike to verify if the problem lays here. Andy. Link to comment
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